Magneto-alternator.



No. 807,949. PATENTED DEC. 19, 1905. L. J. LE PONTOIS.

MAGNBTO ALTERNATOR.

APPLICATION FILED 001201904.

2 SHEETS SHEET 1.

@Whhemao a ag k W 3% M W No. 807,949. PATENTED DEC. 19, 1905.

L. J. LE PONTOISx MAGNETO ALTERNATOR. APYLIQATION FILED oc'r. 20.1904.

2 SHEETSSHEET 2.

UNITED STATES PATENT OFFICE.

LEON JULES LE PONTOIS, OF NEW ROCHELLE, NEW YORK, ASSIGNOR TO POLY-PHASE IGNITION SYSTEM COMPANY, A CORPORATION OF NEW YORK.

IVIAGNETO ALTERNATOR.

Specification of Letters Patent.

Patented Dec. 19, 1905.

Application filed October 20, 1904. Serial No- 229,310.

T0 00% whmn it may concern.-

Be it known that I, LnoN J ULES Ln PONTOlS, a citizen of the Republic of France, and a resident of New Rochelle, VVestchester county, New York, have invented a certain new and useful Improvement in Magneto-Alternators, of which the following is a specification.

My invention relates to a new type of magneto-alternator especially designed for generating at very low speeds alternating currents suitable for use in connection with the system described and claimed by me in cornpanion applications, Serial Nos. 227,547 and 227,548, filed October 7, 1904. I do not, however, intend to restrict the use of the present invention to that purpose, as it is obvious that the magneto-alternator herein described is capable of general application, as the form of magnet used, which is also included with in the present invention, will give a very dense magnetic field for its size and weight and may be utilized in other connectionsas, for example, in the construction of telephone- Inagnetos. I am aware of the fact that permanent magnets have been constructed of thin steel laminae according to the method of Prof. Jamin, who made in this manner the fieldmagnets of the Gramme dynamo. Instead of using separate steel laminae I construct my magneto from a continuous hardened-steel ribbon wound in a circular, oval, rectangular, square, or other form.

My invention will be understood by refer ence to the accompanyingdrawings,in which- Figure 1 is a View, partly in section and partly in elevation, of a two-phase generator, certain of the parts being broken away. Fig. 2 is a front view of the stationary element of the generator, and Fig. 3 is a similar view of the moving element 01' said generator hereinafter designated as the inductor.

Similar reference-numerals indicate similar parts in the several views.

Referring to the drawings, the numeral 1 designates a portion of the crank-casing of the motor, said casing having a bearingfor the motor-shaft 2. The end of the casing is formed with a hub 3, constituting a support or bearing for a spider 4, the latter preferably made of non-magnetic material. An annular permanent magnet 5 is rigidly supported by the spider, said magnet being formed of -a steel ribbon continuously wound in the form of a helix after it has been hardened.

Instead of winding in a circular or ring form the steel ribbon may be wound in the form of an oval, a rectangle, or square. Suitable insulating material is interposed between adjacent convolutions of the ring. The spider 4 is capable of adjustment about its axis in order that it may be so adjusted that the period of current generation will coincide with that period of the piston-stroke at which a spark is required. After having been once adjusted the spider 4 and the magnet carried by it is fixed in position.

After thesteel ring has been securely fastened to the spider 4 it is accurately ground at two opposite zones of the same diameter and placed in a powerful magnetic circuit closing itself by the two zones and by each side of the magnet. Two opposite magnetic poles are thus developed in the zones. An annular segment 6, of annealed wrought-iron, constituting a polar projection is securely fastened to one of the zones by bolts 7, special care being taken that said segment fits perfectly over the whole surface of the zone in order to reduce the reluctance of the magnetic joint to a minimum. An annular segment 8, also made of annealed wrought-iron, is socurely fastened by similar means to the lower or other zone, the zone-surface covered by the segment8 being equal to the surface covered by the upper segment 6. The segment 8 has integral therewith two polar projections 9 and 10, set radially with reference to the center, the angle between the two sides of each of said projections being in the case illustrated thirtytwo degrees. It can thus be readily seen that the magnetic field concentrated about the mag netic poles 6, 9, and 10 closes itself throughout space from poles 9 and 10 to pole 6. Two coils 11 and 12 are wound on the polar projections 9 and 10, respectively.

Although it is evident that it is possible to provide both pole-pieces 6 and 8 with similar and opposite polar projections 9 and 10, having coils l1 and 12, in which coils current will be generated by the change in the magnetic reluctance of the polar projections causedv by the rotation of the inductor, yet in practice I prefer to modify by the rotation of the inductor the reluctance of the polar projections of one of the poles, maintaining the reluctance of the other pole practically constant. While this will result in an uneven magnetic pull exerted by the pole-pieces 6 and 8 on the inductordisk, no apparent trouble is caused, owing to the very strong mechanical construction of both the inductor and the stator. If four polar projections are used instead of two, the coils located on the same diameter should be connected either in parallel or in series, as the currents flowing through them at any given time are in phase with each other.

13 designates the fly-wheel of the motor mounted on shaft 2. For convenience of illustration I have selected said fly-wheel to serve as an inductor. Although as its function consists mainly in permitting the magnetic field, concentrated, respectively, aboutpoles 6, 9, and 10, to close its circuit through the polar projections l t and 15 on the inductor and the central mass of the inductor, it is obvious that any disk of suitable material would answer the same purpose, the object of the construction shown being to design the generator in a more compact form and to make it an integral part of the motor itself. The inductor 13 is so mounted on the shaft 2 as to rotate in close proximity to the polar projections of the magnet, suitable means being provided to prevent any possible side motion of the inductor, which rotates within about one sixty-fourth of an inch of said polar projections. As the inductor is rotated it will cause variations in the intensity of the magnetic flux threading through the coils 11 and 12, and these coils will therefore become the seats of alternating currents differing in phase from each other.

Instead of mounting the inductor directly on the shaft 2, so as to rotate at the same speed therewith, it may be so connected by suitable means to said shaft so as to rotate at such speed or at a multiple of the speed of the shaft 2.

As the inductor rotates at the same speed relation between that period of the pistonstroke during which sparking must occur at some definite time, according to the piston speed, and the period of current generation during which sufficient current for sparking purposes is generated at all times.

The drawings show the polar projections 6, 9, and 10 as slotted in order toprevent closed circuited currents around the edges of said projections.

What I claim, and desire to secure by Letters Patent, is

1. An alternating-current generator having a field-magnet consisting of a permanentlyniagnetized ring formed of a continuous steel ribbon, pole-pieces located at opposite ends of the same diameter and coils supported thereon, and an inductor mounted to rotate in close proximity to said pole-pieces.

2. A field-magnet consisting of a permanently-magnetized ring formed of a continuous steel ribbon.

3. A field-magnet consisting of a permanently-magnetized ring formed of a continuous steel ribbon with insulating material interposed between adjacent convolutions.

I. An alternating-current generator having a field-magnet consisting of a permanentlymagnetized ring formed of a continuous steel ribbon, pole-pieces located at opposite ends of the same diameter, a plurality of projections on one of said pole-pieces, coils surrounding said projections, and an inductor mounted to rotate in close proximity to said pole-pieces.

In testimony whereof I have hereunto signed my name in the presence of two subscribing witnesses.

LEON J ULES LE PONTOIS.

Witnesses:

E. I PORTER, CHARLES S. JONES. 

